I don't think the 2 speed housing broke because of shifting too hard. Else, you'll have the fastest engine on the track. Never happened to me. Just the 2 speed housing wears out over usage. Perhaps some debris caught on and somehow ripped the aluminum housing apart? Or the 2 speed screw is too much out that it "catches" on the holes of the 2 speed housing and ripped it. That's the only thing I can think off...

Other than that, the only other thing that comes into my mind is to claim warranty from Uncle Crash.